In 1876, shortly after the Meiji Restoration, Japan, in commemoration of the 100th anniversary of American independence, sent numerous carpenters to the Philadelphia Centennial Exposition. On a vast site that rivaled those of advanced countries at the time, Japan constructed a dedicated pavilion showcasing Japanese architecture. There, they exhibited a wide range of Japanese products with the aim of promoting exports and earning foreign currency. Japan’s exhibits garnered significant interest and acclaim, rapidly elevating Japan’s reputation, even though it had been considered a backward nation. A reporter from the New York Herald went so far as to write, ‘Why should we call Japan a nation still in the process of civilization when it surpasses France in bronze products and silk, and leads the world in woodworking, furniture, and ceramics?’
Among the exhibits, there was kudzu, which became extremely popular at the exposition. The kudzu plant, with its beautiful flowers, was not only visually appealing but also a favorite food for cattle and horses. Being a leguminous plant, kudzu had symbiotic bacteria in its roots that improved soil quality, and its roots and vines also helped stabilize the edges of fields and roads. As a result, it quickly spread throughout the United States.
However, the vitality and reproductive ability of Kudzu became a disaster, and after that, “Kudzu” came to be referred to as “Vine that ate the South” and “Green monster”, and was also listed as one of the “World’s 100 Worst Invasive Alien Species”.

1876年、アメリカ独立100周年を記念して開催されたフィラデルフィア万国博覧会に、明治維新間もない日本は多数の大工を派遣し、当時の先進国に見劣りしないほどの広大な敷地に日本家屋の専用パビリオンを建てました。そこには、輸出振興と外貨獲得を図るための日本のあらゆる産品が展示されました。そして日本の出展物は後進国と見なされていた日本への関心と評価を一気に高めました。『ニューヨーク・ヘラルド』紙の記者は、「ブロンズ製品や絹ではフランスに優り、木工、家具陶磁器で世界に冠たる日本をなぜ文明途上と呼べるだろうか」と言う記事まで書きました。
その出展物の中にクズがありました。博覧会では大人気になりました。花が美しいうえに、飼料として牛や馬の大好物。マメ科植物なので根に共生するバクテリアが土壌を改良し、さらに根やつるが畑や道路の周縁を固めてくれるというわけで、瞬くうちに全米に広がりました。
しかし、クズの生命力と繁殖力が災いし、その後、「kudzu」は「Vine that ate the South（南部を食べてしまったツル）」とか「green monster」と言われる様になり、「世界の侵略的外来種ワースト100」にも指定される様にもなりました。